src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.loop.phases/src/org/graalvm/compiler/loop/phases/ReassociateInvariantPhase.java

*** 24,49 ****
  
  import org.graalvm.compiler.debug.DebugContext;
  import org.graalvm.compiler.loop.LoopEx;
  import org.graalvm.compiler.loop.LoopsData;
  import org.graalvm.compiler.nodes.StructuredGraph;
  import org.graalvm.compiler.phases.Phase;
  
  public class ReassociateInvariantPhase extends Phase {
  
      @SuppressWarnings("try")
      @Override
      protected void run(StructuredGraph graph) {
!         if (graph.hasLoops()) {
!             final LoopsData dataReassociate = new LoopsData(graph);
              DebugContext debug = graph.getDebug();
              try (DebugContext.Scope s = debug.scope("ReassociateInvariants")) {
                  for (LoopEx loop : dataReassociate.loops()) {
!                     loop.reassociateInvariants();
                  }
              } catch (Throwable e) {
                  throw debug.handle(e);
              }
-             dataReassociate.deleteUnusedNodes();
-         }
      }
  }
--- 24,59 ----
  
  import org.graalvm.compiler.debug.DebugContext;
  import org.graalvm.compiler.loop.LoopEx;
  import org.graalvm.compiler.loop.LoopsData;
  import org.graalvm.compiler.nodes.StructuredGraph;
+ import org.graalvm.compiler.nodes.calc.BinaryArithmeticNode;
  import org.graalvm.compiler.phases.Phase;
  
+ /**
+  * Rearrange {@link BinaryArithmeticNode#isAssociative() associative binary operations} so that
+  * invariant parts of the expression can move outside of the loop.
+  */
  public class ReassociateInvariantPhase extends Phase {
  
      @SuppressWarnings("try")
      @Override
      protected void run(StructuredGraph graph) {
!         int iterations = 0;
          DebugContext debug = graph.getDebug();
          try (DebugContext.Scope s = debug.scope("ReassociateInvariants")) {
+             boolean changed = true;
+             while (changed) {
+                 changed = false;
+                 final LoopsData dataReassociate = new LoopsData(graph);
                  for (LoopEx loop : dataReassociate.loops()) {
!                     changed |= loop.reassociateInvariants();
!                 }
!                 dataReassociate.deleteUnusedNodes();
!                 iterations++;
!                 debug.dump(DebugContext.VERBOSE_LEVEL, graph, "after iteration %d", iterations);
              }
          } catch (Throwable e) {
              throw debug.handle(e);
          }
      }
  }